1 files changed, 6 insertions, 0 deletions
diff --git a/src/wasm/wat-parser.cpp b/src/wasm/wat-parser.cpp
index 3961cbb7f..bdd1af0d8 100644
--- a/src/wasm/wat-parser.cpp
+++ b/src/wasm/wat-parser.cpp
@@ -849,6 +849,7 @@ struct ParseDeclsCtx : NullTypeParserCtx, NullInstrParserCtx {
   void addFuncType(SignatureT) {}
   void addStructType(StructT) {}
   void addArrayType(ArrayT) {}
+  void setOpen() {}
   Result<> addSubtype(Index) { return Ok{}; }
   void finishSubtype(Name name, Index pos) {
     subtypeDefs.push_back({name, pos, Index(subtypeDefs.size())});
@@ -1078,6 +1079,8 @@ struct ParseTypeDefsCtx : TypeParserCtx<ParseTypeDefsCtx> {
 
   void addArrayType(ArrayT& type) { builder[index] = type; }
 
+  void setOpen() { builder[index].setOpen(); }
+
   Result<> addSubtype(Index super) {
     if (super >= builder.size()) {
       return in.err("supertype index out of bounds");
@@ -3463,6 +3466,9 @@ template<typename Ctx> MaybeResult<> subtype(Ctx& ctx) {
   }
 
   if (ctx.in.takeSExprStart("sub"sv)) {
+    if (ctx.in.takeKeyword("open"sv)) {
+      ctx.setOpen();
+    }
     if (auto super = maybeTypeidx(ctx)) {
       CHECK_ERR(super);
       CHECK_ERR(ctx.addSubtype(*super));